Generally in the field of sinus surgery, arthroscopic cutting instruments have been used which instruments have encountered numerous problems, the primary one being that the instruments clog or jam from tissue buildup as there is little fluid present at the sinus surgery site unlike the abundance of fluid which occurs in the joints of a human being. Furthermore, when fluid is used with such instruments, it is excessively applied at the surgical site. The tissue jamming or clogging requires frequent cleaning or substitution of the prior art instruments which is not only time consuming thus increasing the time of the procedure as well as decreasing the number of procedures possible in a given operating room facility but also contributes to physician fatigue thus increasing the chances of error.
The following patents constitute representative types of prior art instrumentation directed toward tissue removal.
The prior art is replete with numerous surgical instruments utilizing a cutting tube mounted within an outer cutting housing, the inner cutter member being hollow and connected to a source of suction. These cutting tubes either rotate or reciprocate within the outer tube housing. Examples of such cutting instruments are shown in U.S. Pat. No. 5,324,301, issued on Jun. 28, 1994, and U.S. Pat. No. 5,286,253, issued on Feb. 15, 1994, the latter showing a similar apparatus with a toothed rotating cutter. In such instruments, the cut tissue and other severed material is generally aspirated into a chamber which has a suction removal conduit communicating perpendicularly with the axis of the tubular cutting member or flow of the surgical debris. In U.S. Pat. No. 4,983,179, issued on Jan. 3, 1991, suction is run through the instrument body to a trap in the suction source. Another U.S. Pat. No. 4,274,414, issued on Jun. 23, 1981, discloses an arthroscopic cutter having a coupling member with a central chamber which deflects fluid and tissues cut by the cutter into a cutter tube to a suction box. Another arthroscopic surgery instrument with a blunt cutter tip and similar construction is shown in U.S. Pat. No. 4,203,444, issued on May 20, 1990. A variety of cutter tips which can be used with arthroscopic surgical instruments are shown in U.S. Pat. No. 4,705,038, issued on Nov. 10, 1987, which patent also shows a suction source which extends from the cutter tube through the instrument body exiting out the rear. A cutting lipectomy device which has the suction flowing along a rigid tube parallel to the instrument body is shown in U.S. Pat. No. 4,815,462 issued on Mar. 28, 1989.
U.S. Pat. No. 5,403,276 issued Apr. 4, 1995 is directed toward a combined tissue removal system which uses a reciprocating cutting blade and feedback control for aspiration and irrigation circuits used in the system. Aspiration and suction is varied to the cutting instrument through a foot pedal which is controlled by the operator to set and maintain via valving and transducers the aspiration vacuum and irrigation pressure of the system.
Attempts to overcome clogging and jamming of these types of instruments due to collection of tissue and other materials which have been severed from the body during cutting while performing the surgical procedure has been to attempt to remove these materials so that they will not have a chance to collect in the instrument or pausing during surgery and breaking down and cleaning the instruments. Unfortunately, the cleaning of these instruments can be difficult and time consuming in a surgical environment.
U.S. Pat. No. 4,108,182, issued on Aug. 22, 1978, shows a surgical instrument with a removable cutter head. The cutter head is provided with a single lumen exterior conduit leading either to the suction or the fluid source so that fluid or suction can alternately be provided along the single lumen flexible tube to the hollow cutting tube. U.S. Pat. No. 5,059,204 issued on Oct. 22, 1991 discloses an ocular guillotine cutter placed within a swagged outer needle. The cutting head has two removable parts, an infusion sleeve which is provided with a passage for transmission of fluid to the cutting site; and an aspiration sleeve provided with a passage which provides for suction which sucks material through the reciprocating cutter tube from the surgical site. The aspiration sleeve fits on the handpiece by a bayonet pin and the infusion sleeve fits over a collar of the aspiration sleeve in an interference fit.
The present invention has overcome the problems inherent in the prior art devices by providing a dual passage, removable manifold which can be easily removed, cleaned or replaced and a double lumen flexible tube. The cutter head body into which the manifold is mounted is also easily removed from the apparatus.
The double lumen flexible tube which supplies both the suction and fluid is mounted in a channel cut into the instrument body with the tube terminating at one end of the removable manifold. Thus, separate passageways for suction and fluid are provided in the invention. It should be noted that in arthroscopic surgery, there is normally a great deal of fluid present at the site of the surgery so that fluid is not required, but in sinus surgery which is the primary direction of the present invention, there is little moisture, so moisture must be supplied to keep the tissue material from clogging up the device.
The instrument is also provided with a nipple projection extending into the tube channel so that a surgeon can easily grasp the flexible tube and with slight finger pressure, decrease the amount of suction or the amount of fluid going to the operation site.